Blue Lug original light.
Tiny but powerful.
The light luminates 20 lumen and has just 2 lighting mode, steady and blink.
The battery lasts for maximum of 20 hours (nominal value) and rechargeable with an USB cable.
When you need to recharge, the light can be detached from a mounting tip.
Including 2 types of bolts, you could easily install the light on pretty much any part of your bike.
